I have a 2018 chevy equinox premier awd with 1.5 turbo and 70,000 miles. it’s in very good shape, there’s nothing wrong with it. my mechanic checked all fluids and verified that I got a good car. It runs and drives very well but sometimes the fuel trim seems a little high. at idle the highest i’ve seen it is -3.5% but when I drive it’s been perfect from 0 but the highest i’ve seen when driving is -5%. fuel trim is almost never positive. Should I look into this more?
Is that long term or short term fuel trim you're talking about?
my mechanic checked all fluids and verified that I got a good car.
It may be OK now, but you should be aware of failure trends for that model.
it is mainly long term fuel trim but a little bit of both. the car doesn’t burn any oil and i change it every 5,000 miles and still get the factory mpg.
The percentage off you're seeing is not terrible, I'd just keep an eye on it. The general rule of thumb is no more than 10%.
https://gtc.ca/blog/long-term-fuel-trim-and-short-trim-fuel-trim/